The two-and-a-half minute GMB clip captures the oddness of his run:

• Bolton is making this announcement on a television show that doesn’t air in the U.S. (Just consider that for a moment.)
• He says he’d run “primarily on the basis that we need a much stronger foreign policy.” That feels a little on the nose, as being a warmonger is the only thing Bolton is known for: He has admitted to planning foreign coups on national TV, and he was fired as national security adviser because he kept trying to start wars after promising Trump that he wouldn’t.
• Bolton suggested that he could beat Trump in 2024, because “Trump’s support within the party itself is in terminal decline.” But Bolton skips over the fact that he  has essentially zero support in the GOP. Beating Trump sounds fine — it’s getting people to vote for Bolton that’s the issue. As GMB interviewer Noel Phillips noted, “His opponents say he lacks in popularity, but a defiant John Bolton is preparing for a fight.”
• Bolton seems set on alienating British people too. He spent part of the interview defending former U.K. prime minister Liz Truss, who was ousted after 44 days, and her wildly unpopular economic policies.

Here's a plausible - and desirable - scenario: the Republican Party nominates DeSantis, Trump can't stand it and runs as an Independent; the Democrats, who have quite sensibly nominated someone besides Biden, win.